TY - JOUR
T1 - Novel drivers and modifiers of MPL-dependent oncogenic transformation identified by deep mutational scanning
AU - Bridgford, Jessica L.
AU - Lee, Su Min
AU - Lee, Christine M.M.
AU - Guglielmelli, Paola
AU - Rumi, Elisa
AU - Pietra, Daniela
AU - Wilcox, Stephen
AU - Chhabra, Yash
AU - Rubin, Alan F.
AU - Cazzola, Mario
AU - Vannucchi, Alessandro M.
AU - Brooks, Andrew J.
AU - Call, Matthew E.
AU - Call, Melissa J.
N1 - Funding Information:
This work was supported by the Australian National Health and Medical Research Council (NHMRC; project grant 115734, program grant 1054618, and Independent Research Institute Infrastructure Support Scheme [IRIISS] infrastructure support) and Victorian State Government Operational Infrastructure Support (to Walter and Eliza Hall Institute [WEHI]). Research was carried out in part at the Translational Research Institute (Woolloongabba, QLD, Australia), which is supported by a grant from the Australian government. Molecular characterization of patients followed at the University of Florence and the University of Pavia in Italy was supported by Associazione Italiana per la Ricerca sul Cancro (AIRC; 5x1000) call “Metastatic disease: the key unmet need in oncology” to the MYNERVA project (#21267).
Publisher Copyright:
© 2020 by The American Society of Hematology
PY - 2020/1/23
Y1 - 2020/1/23
N2 - The single transmembrane domain (TMD) of the human thrombopoietin receptor (TpoR/ myeloproliferative leukemia [MPL] protein), encoded by exon 10 of the MPL gene, is a hotspot for somatic mutations associated with myeloproliferative neoplasms (MPNs). Approximately 6% and 14% of JAK2 V617F2 essential thrombocythemia and primary myelofibrosis patients, respectively, have “canonical” MPL exon 10 driver mutations W515L/K/R/A or S505N, which generate constitutively active receptors and consequent loss of Tpo dependence. Other “noncanonical” MPL exon 10 mutations have also been identified in patients, both alone and in combination with canonical mutations, but, in almost all cases, their functional consequences and relevance to disease are unknown. Here, we used a deep mutational scanning approach to evaluate all possible single amino acid substitutions in the human TpoR TMD for their ability to confer cytokine-independent growth in Ba/F3 cells. We identified all currently recognized driver mutations and 7 novel mutations that cause constitutive TpoR activation, and a much larger number of second-site mutations that enhance S505N-driven activation. We found examples of both of these categories in published and previously unpublished MPL exon 10 sequencing data from MPN patients, demonstrating that some, if not all, of the new mutations reported here represent likely drivers or modifiers of myeloproliferative disease.
AB - The single transmembrane domain (TMD) of the human thrombopoietin receptor (TpoR/ myeloproliferative leukemia [MPL] protein), encoded by exon 10 of the MPL gene, is a hotspot for somatic mutations associated with myeloproliferative neoplasms (MPNs). Approximately 6% and 14% of JAK2 V617F2 essential thrombocythemia and primary myelofibrosis patients, respectively, have “canonical” MPL exon 10 driver mutations W515L/K/R/A or S505N, which generate constitutively active receptors and consequent loss of Tpo dependence. Other “noncanonical” MPL exon 10 mutations have also been identified in patients, both alone and in combination with canonical mutations, but, in almost all cases, their functional consequences and relevance to disease are unknown. Here, we used a deep mutational scanning approach to evaluate all possible single amino acid substitutions in the human TpoR TMD for their ability to confer cytokine-independent growth in Ba/F3 cells. We identified all currently recognized driver mutations and 7 novel mutations that cause constitutive TpoR activation, and a much larger number of second-site mutations that enhance S505N-driven activation. We found examples of both of these categories in published and previously unpublished MPL exon 10 sequencing data from MPN patients, demonstrating that some, if not all, of the new mutations reported here represent likely drivers or modifiers of myeloproliferative disease.
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U2 - 10.1182/blood.2019002561
DO - 10.1182/blood.2019002561
M3 - Article
C2 - 31697803
AN - SCOPUS:85078380034
SN - 0006-4971
VL - 135
SP - 287
EP - 292
JO - Blood
JF - Blood
IS - 4
ER -